This invention relates to a method of preparing thermally stable resinous block polymers.
Resinous block polymers of styrene and conjugated dienes have been known for some time and are now used commercially in a wide variety of applications. Such polymers have been found useful for various applications including injection molding, extrusion and the like. The conjugated diene portion of these known styrene/diene resinous polymers, whle contributing to the overall polymer properties such as impact strength, tends to make the polymers susceptible to thermal instability. It has been found that both styrene/butadiene copolymers and styrene/isoprene copolymers exhibit thermal instability. Accordingly, this limits their usefulness in applications which involve exposure to high temperatures.